High tension switch jaw assembly



June 20, 1933. T. F. JOHNSON, JR 1 HIGH TENS ION SWITCH JAW ASSEMBLY Filed March 28, 1950 2 Sheets-Sheet 1 IHIIU lllllllll INVENTOR ATTORNEYS June 20, 1933. T. F. JOHNSON, JR 1,914,777

HIGH TENSION SWITCH JAW ASSEMBLY Filed March 28, 1950 2 Sheets-Shem. 2

iNVENTOR 5&1?

ATTORNEY' S Patented June 20, 1933 UNITED STATES PATENT OFFICE HIGH TENSION SWITCH JAW ASSEMBLY Application filed March 28, 1930. Serial No. 439,700.

This invention relates to high tension knife switches and, among other objects, aims to provide an improved bracket and jaw assembly wherein separate jaw members are adjustably and resiliently mounted and the resilient supports or members are relieved of shearing or compression stresses when the blade is forcibly closed.

This application involves important improvements on the jaw assembly disclosed in my Patent No. 1,749,537 issued March 4, 1930.

In the accompanying drawings:

Fig. 1 is a side elevation showing one embodiment of the invention;

Fig. 2 is a top plan View of Fig. 1;

Fig. 3 is a sectional view taken on the line 33 of Fig. 1;

Fig. 4C is a sectional View taken on the line 4-4: of Fig. 1;

Fig. 5 is a perspective view showing a resilient supporting member for one of the switch jaws; and

Fig. 6 is a fragmentary side elevation of the end of the switch blade.

Referring particularly to the drawings, the jaw assembly is there shown as being mounted on an elongated bracket 10 presenting a base in the form of opposed flanges 11 adapted to be secured to a post insulator (not shown). At one end of the bracket there is shown a horizontal arm12 on which is secured a suitable socket or wire connecting member 13 for a transmission-conductor (not shown) while the switch jaws 1 1 are supported adjacent to the opposite end, each jaw being electrically connected to the line connector by flexible conductors 15. These conductors are conveniently secured by bolts to horizontal flanges 16 cast integral with the jaws and projecting outwardly therefrom (Figs. 1, 2 and 3), the arrangement being such that no current has to be conducted through the jaw supports.

The front end of the bracket is here shown as having an elongated, horizontal shelf 17 arranged to support the weight of the aws and also to act as a limiting stop for the switch blade 18. The idea is to relieve the jaws and their resilient mountings of any breaking stresses when the switch blade is.

rapidly and forcibly closed. To strengthen or reinforce the supporting shelf, a vertical web 19 is preferably cast integral with the bracket as shown in Figs. 1 and 4;.

Herein, the main bracket has an upstanding or vertical arm 20 in the form of a thick wall above the rear end of the shelf 17 and a pair of resilient, L-shaped plates 21 of sheet metal between which the jaws are mounted are removably secured to the front face of this wall. The mode of securing the plates may be and preferably is similar to that shown in my aforesaid patent, the bent ends having notches 22 cut in the plate flanges which will fit in channels between flanges 23 on the wall (Figs. 1 and 5). The flanges 23 are slotted at their ends to receive the ears 24k or T-shaped ends of the plate flanges so thatthe plates are interlocked with the bracket supporting wall. They are secured in this position by a single bolt 25 passing through alined openings in the plates and their spring {fliSlOIl may be adjusted or varied by this The jaws are herein held assembled between the spring plates by means of integral projections 26 passing through openings 27 near the ends of the plates (Fi s. 3 and 5). The openings 27 are somewhat larger than the pins or projections 26 to permit the jaws to have some lost motion or play and to insure that their lower edges will rest upon the shelf 17 (Fig. 4). Each of the jaws also has a rounded protuberance or projection 28 adapted to have rocking contact with the inner faces of the spring plates so that the aws will automatically adjust themselves against the side faces of the switch blade-l8 and provide a good electrical contact. The enlarged openings 2'7 for the pins 26 permit adequate rockingmovement of the jaws and, at the same time, prevent the jaws from bein displaced longitudinally relative to each other. Moreover, the lengths of the pins are such that neither jaw can be removed or disengaged from its spring plate without first removing one of the plates.

In this example, each jaw has an integral ear or lug 29 at its lower edge near the main bracket. These ears or lugs not only provide a larger bearing surface for the aws against the shelf 17, but engage the lower edges of the spring plates when the switch blade is forcibly swung open, thus relieving the pins 26 of some of the shearing stress. This also reduces the shearing strain on the plates at their rear or bracket ends.

Referring to Figs. 3, 4 and 6, the jaw-engaging portion of the switch blade 18 is shown as having a reduced nose portion 30 at its lower and end edges, the lower corner being rounded on a relatively large arc- The reduced or thin edge is adapted to strike against the shelf without battering or u setting the contacting faces of the blade. f the lower edge of the blade were slightly thickened or upset upon striking the shelf, the side faces would not contact with the faces of the jaws throughout the width of the blade. Such good contact is essential to prevent arcing.

It is contemplated that the blade may be jointed elbow-fashion intermediate its ends as shown in Fig. 6 so that, upon entering the jaws, the end will point downwardly at an angle to the horizontal until it enters the jaws and/or strikes the shelf (see the dotted position in Fig. l), whereupon it will straighten out. This will impart a longitudinal wiping or sliding movement to the contact end of the blade. To insure that such a blade will be guided properly into the jaws, the jaws are flared outwardly both at their upper and front edges,'as shown in Fig. 2.

To assemble the jaws, one of the L-shaped sprin plates may be inserted in its channel and then the aw may be set in place with its pin 26 projecting through the opening 37. The other jaw may then be assembled on its spring plate by inserting the pin 26 through its opening before the rear flange of the spring plate is inserted in its channel. The second spring plate is then pushed home so that the cars 24 are seated in the bottom of their slots and the bolt 25 is then passed through the the alined openings in the plates to secure them in the proper adjusted positions. The nut on the bolt may be tightened so as to cause the 'aws to exert great gripping pressure on lade. The idea is to permit the blade to close without striking the shelf too hard and to insure that the jaws will remain in gripping surface contact with the opposite faces of the blade.

From the foregoing description, it will be seen that all of the parts of the jaw assembly can be made very cheaply. Both of the jaws and the supporting brackets can be made of suitable cast metal; while the spring plates can be fashioned out of fiat sheet metal. It will be further noted that only one bolt is required to hold the parts assembled and the spring plates are relieved of shearing stresses incident to closing movements of the blade. Furthermore, any part of the assembly may be removed very quickly and replaced in case it is necessary to make any repairs, thus eliminating great loss of time and line outage.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

What is claimed is 1. In a knife switch of the character described, a vertical supporting bracket; a pair of leaf spring members removably secured at their rear ends to the bracket; a pivotal blade switch jaws loosely mounted between the spring members and having provision to be rocked relative thereto so as to aline themselves with the switch blade; and a horizontal shelf on the bracket to limit the closing movement of the blade and supporting the weight of the jaws torelieve the spring members of bending strains when the switch is being closed.

2. In a knife switch of the character described, a vertical supporting bracket; a pair of horizontal spring members reniovably secured at their rear ends to the bracket; switch jaws loosely mounted between the spring members and having provision to be rocked relative thereto so as to aline themselves with the switch blade; and a horizontal shelf member on the bracket supporting the entire weight of the aws arranged to limit the closing movement of the blade.

3. In a knife switch of the character described, an upstanding bracket adapted to be mounted on an insulator; a pair of horizontal and approximately parallel spring plates secured to the bracket; switch jaws loosely and removably mounted between said spring plates; 'a pivoted switch blade adapted to swing in a vertical plane and a horizontal shelf on the bracket below said spring plates providing a support for the entire weight of the jaws and a stop to limit the closing movement of the switch blade.

4. In a knife switch of the character described, a bracket presenting a vertical wall; a pair of L-shaped spring plates removably secured to one face of the wall and projecting horizontally therefrom; a jointed switch blade adapted to swing in a vertical plane; switch jaws loosely and removably mounted between said plates and having provision to rock relative thereto so as to align themselves with the switch blade; and a horizontal shelf on the bracket supporting the entire weight of the jaws and providing a limiting stop and guide for the switch blade during the closing movement.

5. In a knife switch of the character described, a bracket presenting a vertical wall; a pair of spring plates removably secured to oneface of the wall and projecting horizontally therefrom; switch jaws loosely and removably mounted between said plates and having provision to rock relative thereto so as to align themselves with the switch blade; a jointed switch blade adapted to swing in a vertical plane; and a horizontal shelf on the bracket supporting the entire weight of the jaws and providing a limiting stop for the switch blade, said blade having its striking edge reduced in thickness below the contacting faces to prevent the contacting portion from being upset upon striking the shelf.

6. In a high tension knife switch of the character described a pivoted switch blade adapted to swing in a vertical plane; a bracket adapted to be mounted on an insulator and presenting a substantially vertical wall; a pair of L-shaped spring plate members each having one flange slidably and removably secured to said vertical wall and projecting horizontally therefrom; said projecting flanges having openings adjacent to their free ends; switch jaws presenting outwardlyprojecting pins inserted through said openings and of smaller diameter than said 0 enings to permit limited movement of the aws therein; protuberances on the outer walls of said jaws adapted to contact with the inner faces of said plates to permit limited rocking movement of the jaws so that they will aline themselves automatically with the contact faces of the switch blade; and outwardly projecting ears at the lower edges of said jaws adjacent to their rear ends adapted to contact with the lower edges of said plates.

7 In a high tension knife switch of the character described, a bracket presenting a substantially vertical wall; a pair of approximately parallel spring plates secured to one face of said wall and projecting horizontally therefrom; switch jaws mounted between said spring plates and having outwardly flared upper and forward edges to guide the tip of a jointed blade between them; each of said jaws presenting an integral, outwardly projecting pin; said plates having enlarged openings receiving said pins and permitting limited vertical and rocking movement of said jaws; protuberances on the outer walls of said jaws adapted to contact with the innor faces of said plates to permit rocking movement of the jaws; outwardly projecting ears formed on the lower edges of said jaws adjacent to their outer ends and adapted to contact with the lower edges of said spring plates when the switch blade swings open; and a shelf on the bracket supporting the weight of said jaws and providing a stop to limit the closing movement of the blade.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature.

TOMLINSON FORT JOHNSON, JR. 

